Friction draft gear



M. VAN LOAN, JR

Jan. 9, 1945.

. FRI-CTION DRAM! GEAR Filed May ,7, 1945 infested4 Jan. 9, .194s

UN I TED" STATES PATENT i OFFICE ,i ,n `22,366,318 ,l

` FRIC'lION DRAFT GEAR n Morton VanLoanJr., lEvanston, Ill., assignor to i Peerless Equipment Company,` Chicago, Ill., a corporation of Delaware i Application May?, 1943, Serial No. 486,062 l (c1. `21e-si) 10 Claims.

This invention relates to railway draftgears, and has particular reference to improvementsin railway draft gears of the general type compris- 'ing a` casing, friction shoes therein, resilient Vmeans reacting from the rear end ofthe casing forwardly upon said friction shoes, anda wedge 'element for exerting force-rearwardly and outwardly upon said frictionishoes in response to `draft andbuing forces imposed upon the gear, whereby the shoes are caused `to4 cooperate frictionally with the casing to vresist said forces.

One special and important object of the invention is to provide'a ldraft gear of the general type mentioned embodying a` simple, practical construction whereby it may accept impact blows delivered 'angularly thereto, without distortion,

n breakage or disalinement of the parts thereof.

Another special` and `important object of `the invention is to provide a draft gear of the general typementioned embodying novel and improved spring `means to release the wedge element from' the friction shoes following any given operation of the gear to absorb the shock of a draft or bufiing force imposed thereon, thereby to avoid any sticking ofthe` parts ofthe gear in positions in which they are ineffective properly to perform their shock absorbing functions.

With the foregoing and other objects in view, which will becomemore fully apparent as the nature of the invention is betterunderstood, the same consists in a draft gear embodying the novel featuresof construction, combination and arrangement` of parts as will be hereinafter more 'fully described, illustrated in the accompanying drawing and dei-ined in theappended` claims.

` In the accompanying drawing, wherein like characters of reference :denote corresponding parts in the different views: n

, Figure 1r is a` central, horizontal section through a draftgear constructed in. accordance with one practical embodiment of the invention. Figure 2 `is a cross section on the line 2--2 of Fig. liwith parts broken away.

Figure 3 is a cross section on the line 3-,:3of

i Fig. 1; and

Figure '41is a `perspective view of the release spring unit. f

Referring to the drawing detail, I0, I designatethe side sills of a car under-frame structure; II and I2 designate front and rear pairs of stop lugs fixed to and extending inwardly from said sidesills I0, Ill, andA designates, generally,

a draft gear constructed in accordance with one practical embodiment of the invention and op- `eratively disposed between the side sills I 0, Ill

and between said pairs of stop lugs IIand I2,

all in accordance with` usual` andwell known practice. i

The'draft gear-A comprises, as usual, a sub-` stantially cylindrical casing I3 the front end tion shoes I5 disposed in the said frontend portion of said casing with their outer faces in frici tional sliding engagement with the inwardly tapered inner surface I4 thereof; a spring cap I6 disposed against the rear ends of said friction shoes; one or more coil `springs I1 or other suitable resilient means interposed `between the rear wall I8 ofthecasing I3 and said spring cap and tending constantlyto urge said `friction shoes forwardly relative to said casing, and a wedge` element I9 in front of thefriction shoes l5 and having wedging cooperation therewith whereby it is effective, byrearward movement thereof, to move `said friction shoes rearwardly and also to urge them outwardly against the said inwardly tapered surface I4, all as is likewise, `generally speaking, well knownin the art.

At the front end of the casing I3 is an inward ly extending stop flange 20 or other suitable stop 2 means to be engaged by the `front end of the wedge e1ementl9to limitl forwardmovement thereof, while in accordance with the invention the rear wall I8 ofthe casing I3 is comprised by a plate or'the like separate from said casing so that prior to riveting orctherwise fastening the same to said casing, the parts of the gear which are contained in said casing may be inserted into the same through the open rear end thereof. i'

`In the Wedge element i9` is a recess- 2Iof spherical form which opens through the front end of said wedge element, while neatly fitted in said recess is a substantially spherical head 22 at the rear end of a wedge follower` 23 which extends through the central opening in the front end of the casing I 3 defined` by the stop flange 2li and atits front end is seated against the `rear face of a main front follower 24.

The recess 2l is in excess of a hemisphere so as to insure retention of the head 22 therein, and in this connection, inorderto permit ready assembly and disassemblyof said head 22 with and from the wedge element` I 9, the latter may be composed, as shown, of two mating half-sections which constantly are urgedand `maintained together by their Wedging engagement with the ,i front ends ofthe friction shoes I'5.

ative to said casing `,and maintaining the main front follower 24 engaged against the front pair Aof stop lugs II.` In this connection it will bey understood, of course, that' a draw-bar' (not shown) is engaged with the rear end of the casi ing I3 and with the front face of the mainfront follower 24. Accordingly, assuming that, through the draw-bar, either a draft force is imposed and the rearwardly tapered inner suface ofthe forwardly upon the casing I3 or v.that a puffing force' is imposed rearwardlyupon the main front follower 24;1it`f is"l manifest thatftha. wedge velement I9 will' be forcedI rearwardly relative to the casing I3, that the friction shoes I5 likewise will be forced rearwardly relative to said casing, andvl i" that due to the resistance offered by thespr in g,

or springs, I'I to rearward .movement of said friction shoes, the same will be forcedifoutwardly by the wedge element I9 tightly against -the inwardly tapered inner surface I4 of the casinar I3 and thereby the shock or ignfipact,n of the draft or buing force, as the case may be, will be absorbed by the frictional sliding engagement of l5 Wilhdle @..eelile-ell1eeel4- beetle? between .-.thl .wedeelfellewer `"L3 f .lewerte .assume-e ,la eefe'ef elllentlm Witheet .dlsierea,bfeelkeeefer .llleelinemeet einer ether lef filleflillefenl werte .el the gear.

Fellow/.lee relief lef .e .draft er .bell-lne -.feree imposed veen eheeeer `eweeneirll ef the Serine or springs, Il Vvordinarily, effects,release of the 4gear casing I3 may be of any other desired forrn.v

Without flllther descriptionit isthought that vthe features andgadvantages of the'invention will be readily apparent to those skilled in the art,

mand it will of course be understood that changes' in the form, proportion and minor details of construtignnay be resorted to, without departing from the spirit of the invention and scope of the ;,I,e1aimr 1. 'A Afriction vdraft gear comprising a casing having fan; inwardly tapered inner surface, friction I9 forwardly until 1@the same assume their normal .forwardmost .positions as determined .by engageine'nt of `the lwedge ,element ,L9 ,with the .stop flange 20. u 'In this .connection and to insure initial forward release inovement'of the wedgeele.- ment V|59 relative Vto .the .friction rshoes I5 `in `the event .sai-d 'wedge' element'lshuld tend to .stick againstsaid yfriction shoes .and prevent'the ir forfward release movement, a novel .release 4.Spring u'nit 25 is provided; This 'unit lmprises ,a bleek 26 t6 nt into a cntrai recess 211 inthe rear en@ of the" wedge"elerr'nt.I l';x `a Aplurality of Aother blocks 2,8', one for each of the' friction shoes I5, seated at its' 'outer vside against vits relateolV friction shoe and atfi'tsffraend against the Afront face f lhe$Prlig #all 1:6, ',ellld 'bellied leef. ,Spflg 2,9 Cleg llcf. 'Plflk 2,8' h Ille 1919i* .,35-

.Dile te the Meeks 28 .beleg .held by the spring een" le ieeeinslt `reewiverd'moremeer,' .relative ,te the friction shoes I5, it'is ap arent that as' the wedge elelheflflflfietes rearwardly relative le said friction ShQesunderanimpactforce imiefted 'tei thel'eer, "th'eflef .-SDrleeS 29 will lee abnormally bow d or flexed witli'corisequent storirg" fpln'g" ener' 'tfllelril Aeeeldinely, veen relief ef the leistet relie, pretendenti .er ,said leef sprites te Slreielllen' .er ,te return le their nrmel bewedleleey thereby .te release the energy stored therein Will eifect'forward movement of elle Wedge' eleme'fitmlweletve lle the lriellen shoes I5 and thus' overcome any sticking of said wedge element'ag'ainst said'fiction shoes, instaring"returi 'of`"sai3d"fri`ction'sh Aes :and said wedgeV element Ito "their" frward'mo'st lo'r lreleased yposition'sby' the springib springs',"|1'.

In the' raw'iriggbiilyftwo" been 'illustrated anc'i''these have vbeen Vshown as having' a'plurality Y"of 'flat' outer faces 'cooperating with correspondingilat inner faces of the c'a'sing"I`3. (Dbviously, however, any other number of friction shoes may be provided ifV desired and,'regardless of their numbejrt their outer facesl friction shoes I 5 havel shoeshaving their outer .faces disposed against said surface, a wedge element having wedging eoeperatiqn withthetpllterfendsg-offsaid friction hoes inwardly longitudialso laterally outward imposed -upon vthe gear tarevtransmitted rto #said wedge Seleljxienin vamil a iuniversalgjoint connection between said wedge .follower andrsaid :wedge lement v y i i 2. A friction draft *gear comprising-a `casing having an linwardly 4.tapered linner lsurface, 'fric-r tion shoes having -itheir outer faces disposed against .Said sllrface., a wedge -felement having wedging ico operation-with ,the outer `ends :of said frictio .shoes so ,that :by inward movementthere- Veffectiyf-e rtowurgevsaidshoes inwardly longitudinally of the casing and falso, laterally outward against said tape tendingfconstantl ,urge saidfr-iction lshoes and seid wedge @lemen engltuflinally 4outwardlyre1- top means. tolimit longitud wedge element fill@ @all lillfm Shoes by said spring, a main front follower, a Wedge follower interposed be-` tween .front ,follower and said wedge element and, through ywhich .imp-act :fortes .im-

posed 'upon the gear .are transmitted to said wedgelelement, .and a universal Joint ball and Seeliel; eermeetlen between .said wedge follower and said wedge element.`

VflllliQll. draft igl'mcomprising a `casing eleed at .its rear end and centrally open at its freni sind` and ,having :inwardly extending stop Ill-@alle .et its .front end., .the inner ,surface of the front end portion of saidcasing being tapered llWlldlY, .el plurality .of friction shoes in the front end portion of said casing with their outer f j Wedge element. hating wedgingcooperation with 101.1 shoes, so. that. by

the. frerlt ends Qf. ,sa-ld fri.. rearward mevement thereof it is effective to. move Seid Shees rearwardly and.. 'also outwardly againstv Seid tapered surfaee. said; stop. means. being dief.. D .eee'fl te, be engaged by said. wedge element: to, breit forward. movement thereof and. thereby limit ferward movement of said slides@ a mam.'

front follower, a wedge follower interposed between said main front follower and said wedge Qvementtthereof ittis .d Surface, fresielient A:orleans ing in the front end of said casing and through which impact blows delivered to the gear are transmitted to said wedge element, and a universal joint connection between said wedge follower and said wedge element.

4. A friction draft `gear comprising a casing closed at its rear end and centrally open at its front end and having inwardly extending `stop means at its front end, the inner surface -of the front end portion of said casing being tapered inwardly, a plurality of friction shoes in the front end portion of said casing with their outer faces engaged with said tapered surface, resilient means between the rear end wall of said casing and said friction shoes tending constantly to urge said shoes forwardly relative to said casing, a wedge element having wedging cooperation with the front ends of said friction shoes so that by rearward movement thereof it is effective to move said shoes rearwardly and also outwardly against said tapered surface, said stop `means being dis` resilient means'and against lateral outward'move- `ment by the inner end portions of said shoes,

whereby it holds the inner end portions of said shoes urged outwardly against said casing and posed to be engaged by said wedge element to r limit forward movement thereof and thereby against said surface, a wedge element having wedging cooperation with the outer ends of said friction shoes so` that by inward movement thereof it is effective to urge said shoes inwardly longitudinally of the casing and also laterally outward against said tapered surface, resilient means tending constantly'to urge said friction shoes and said wedge element longitudinally outwardly relative to said casing, stop means to limit longitudinal outward movement of said wedge element and said friction shoes by said spring, a main front follower, a wedge follower interposed between said main front follower and said wedge element and through which impact forces imposed upon the gear are transmitted to said wedge element, said wedge element having a recess of spherical form therein and said wedge followerhaving a head of spherical form disposed in and neatly fitting saidrecess to provide a universal joint-l connection between the same land said wedge element.

6. Afriction draft gear as set forth in claim 5 in which the wedge element is composed of separate mating sections to permit disposition of the l head `of the wedge follower inthe recess of said wedge element. l

'7. A friction draft gear comprising a casing having an inwardly tapered inner surface, friction `shoes having their outer faces disposed against said surface, a Awedge element having wedging cooperation with the outer ends of `said friction shoes so that by inward movement thereof it is effective to urge said shoes inwardly longitudinally of the casing and also laterally outward against said tapered surface, resilient means tending constantly to urge said friction shoes and said wedge element longitudinally outwardly relastantly forwardly upon said spring cap and I is energized by longitudinal inward movement of said wedge element relative to said shoes and exerts a releasing force longitudinally outward upon said wedge element. r

8. A friction draft gear comprising a casing, the inner surface of the front end portion of which is tapered inwardly, a plurality of friction `shoes in the front end portion of said casing with their outer faces engaged with said" tapered surface, a spring cap disposed against the rearv ends i,

of said shoes, resilient means exerting force` constantly forwardly upon said spring cap and i through the same upon said shoes, a wedge element having wedging cooperation with the front end portions of said shoes so that by rearward movement thereof it is `effective to move said shoes rearwardly and also outwardly against said tapered surface, and a release spring unit interposed between said spring cap and the rear end of said wedge element and said friction shoes, said `release spring unit comprising a plurality of leaf springs extending between said wedge element and said spring cap and held at their rear ends by the inner end portions of said :shoes against outward movement and by said spring cap against rearward movement relative to said shoes, whereby they hold the inner end portions of said shoes urged outwardly against said casing and are energized by rearward movement of said wedge element relative to said shoes to subsequently effect releasing forward movement of said wedge element relative to said shoes.

9. A friction draft gear comprising a Vcasing the inner surface of the front end portion of which is tapered inwardly, a plurality of friction shoes in the front end portion of said casingl with their outer faces engaged with said tapered surfaces, a spring cap disposed against the rear ends of said shoes, resilient means exerting force con- `tapered surface,` and a release spring unit interposed between said spring cap and the rear end of said wedge element and said friction shoes, said release spring unit comprising a block disposed against the rear end of said wedge element, a plurality of other blocks disposed against the inner faces o"f said friction shoes, respectively,

and `against the front face of said spring cap, and bowed leafsprings connecting said first mentioned block with said second mentioned blocks, respectively.

10. A friction draft gear as set forth in claim 9 in which the wedge element is provided in its` inner end with a centrally located recess, and in which'therst mentioned block is disposed in said recess and thereby is, held centrally located rela-` tive to said wedge element. r

MORTON VAN LOAN, JR. 

